Rapidly solidified Sm-Co-Hf-B magnetic Nano-composites: Experimental and DFT studies

A. Raja, T. Adhikary, I. A. Al-Omari, G. P. Das, S. Ghosh, D. K. Satapathy, A. Oraon, J. E. Shield, S. Aich*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

The effect of Hf and B additions on the phase stability, microstructure and magnetic properties of the metastable SmCo7 (1:7H) ribbons has been investigated with a combined approach of experimental measurements and first principle DFT (density functional theory) calculations. A series of (Sm0.12Co0.88)95Hf5−xBx (x = 0, 1, 2, 3, 4 and 5) alloys were arc-melted in a TIG (tungsten inert gas) arc melting furnace, followed by melt-spinning onto a copper roller at a wheel velocity of 40 m/s. Characterization based on X-ray diffraction indicates that the major phase is SmCo7 having meta-stable (TbCu7-type) structure. From the total energy calculations using DFT, the phase stability of (Sm0.12Co0.88)95Hf5−xBx ribbons have been confirmed. Moreover, Hf and B addition results in an effective grain refinement; average grain size being as low as ~ 80 nm. The reduction in grain size leads to significant changes (increase or decrease) in magnetic properties depending on the Hf/B ratio. The coercivity value (Hc) varies between 7 kOe and 12 kOe as x (at.% B) increases from 0 to 5 at.%. The experimental coercivity values have been compared with the computed anisotropy energies. The saturation magnetization (Ms) increases from ~ 54 emu/g to 77 emu/g with increasing B concentration (x).

Original languageEnglish
Article number166645
JournalJournal of Magnetism and Magnetic Materials
Volume504
DOIs
Publication statusPublished - Jun 15 2020
Externally publishedYes

Keywords

  • Coercivity
  • First-principle calculations
  • Magnetic moment
  • Phase stability
  • Site preference
  • SmCo ribbons

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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